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Soulskill writes "Brian Wilcox, a JPL roboticist, spoke at a NASA workshop about the possibility of detaching one of the International Space Station's modules and using it as the primary living space for astronauts on a trip to an asteroid. 'The node could be connected to two space exploration vehicles and have add-on inflatable modules. ... The space station is slated to operate through at least 2020, which roughly coincides with the earliest likely launch date for human exploration of an asteroid. In April President Barack Obama set a 2025 goal for a manned mission to an asteroid.'"

The cheapest and safest way to finish the mission would be to load the crew and samples into an apollo style capsule and reenter directly. The article doesn't describe that.

Also the module doesn't seem big enough for the centrifuge they describe. They could have a module on a boom, then rotate the whole vehicle. Perhaps the high gravity module could slide along the boom and dock with the main vehicle. If this goes anywhere I expect the centrifuge will be dropped. It is just too hard to engineer.

Rather than putting the module on a boom, I'd just put jets on the module and spin it up. You wouldn't need constant thrust, but on the down side, it wouldn't be able to put the module on the asteroid proper and you'd have to spin down for docking maneuvers.

Rather than putting the module on a boom, I'd just put jets on the module and spin it up.

Won't work as the module is too small. To get any noticeable gravity at the ends of the module, your spin rate will be high enough to cause dizziness. (Not to mention the area of useful gravity will be small, and the gravity gradient will be very steep.)Which is why most proposals use tethers or booms to give a 'virtual diameter' large enough to hold the spin rate down.

Rather than putting the module on a boom, I'd just put jets on the module and spin it up.

Won't work as the module is too small. To get any noticeable gravity at the ends of the module, your spin rate will be high enough to cause dizziness. (Not to mention the area of useful gravity will be small, and the gravity gradient will be very steep.)

Which is why most proposals use tethers or booms to give a 'virtual diameter' large enough to hold the spin rate down.

How about a toroidal (or cylindrical) running track, with no spin beyond the movement of the runners? It worked on skylab. The main problem is the impulse from the masses moving around.

OTOH aerobraking doesn't have to end up with immediate full reentry; some of our unmanned spacecraft performed many gradual ones when arriving at their destination (and becoming artificial satellites there), many "orbital tug" projects envisioned using aerobraking routinelly, and it is generally an extreme form of skip reentry - a good way to save on weight.

One problem could be how ISS modules are meant for long term habitation inside of Earth's magnetosphere; on deep space missions it will be good to have something built at least partially as a radiation shelter / essentially inside fuel tanks. Which presents another problem with artificial gravity - it's fairly easy when the spacecraft can be easily divided along the crewed mass vs. propulsive mass lines, not so when it's good for them to partially "mixed"...

In the event of a major failure of the spacecraft you need a reasonably fail safe way to get to safety. In the future when there are more deep space vehicles it might be possible to rescue a crew in this situation. Until then, being able to directly reenter and land is a good idea.

To some degree, sure - but the more we venture outside LEO, the less it should matter. Probably if a deep space emergency was so time & guidance critical, better heatshield (remember, useful only for very few destinations) would rarely contribute.

The designs I saw come out of this workshop, which of course are very preliminary, did indeed have direct return vehicles, but the goal is also to get the "mothership" back to Earth so that it can be used for the next asteroid mission, and the next, and the next. The goal being to develop a capability to visit asteroids of greater and greater travel time / delta-v. This is important because we don't get to choose killer asteroids, they choose us, and as the robotic missions guys said on the first day of the conference, they're all surprised they even managed to get data from their missions, and wouldn't want the fate of the human race resting on it.

The designs I saw come out of this workshop, which of course are very preliminary, did indeed have direct return vehicles, but the goal is also to get the "mothership" back to Earth so that it can be used for the next asteroid mission, and the next, and the next.

Getting the "mothership" back into orbit is going to require an enormous amount of fuel to slow down, which means that fuel has to be boosted to the target, slowed down at the target, and boosted back towards Earth... That's going to be very expens

The cheapest and safest way to finish the mission would be to load the crew and samples into an apollo style capsule and reenter directly.

Nah. Just park the ship on the far side of the asteroid and with enough fuel, you can fly the asteroid back home to Earth. Much more living space that way. It would be like building a spaceship out of kit, so we could call this the Kit Technique or 'KT' mission.

In April President Barack Obama set a 2025 goal for a manned mission to an asteroid.

Seeings how much NASA gets pushed and pulled by every administration and every budget I wouldn't count on anything NASA has as far as long term goals being so concrete as to put a date to them. Politicians really need to stop using NASA as a token in a pissing match. It's petty and counterproductive.

Hell, if it weren't for JFK taking a bullet to the head we may have never even gotten to the moon.

"Careful there", my ass. He's quite possibly right in spite of being so refreshingly blunt and transparent... unlike certain creatures who get chosen and paid to make decisions for the rest of us.

Further, I find this lazy-days-of-summer spacefaring timetable ridiculous, if not downright suspicious. THIRTEEN YEARS to plan a mission to an asteroid? It sounds suspiciously like plausible deniability, if you ask me: set a date so far in the future, so many administrations hence, that it's virtually certain to get killed or watered-down before that date arrives.

I don't think you understood the intent of his remark at all. Clearly in hindsight, after seeing your explanation, you thought he was drawing a parallel between Kennedy and Obama and implying that someone should put a bullet to the head of Obama in order to get the space program going again... is that about right?

Well, you misunderstood. Kennedy was noteworthy for the public statements he made about space exploration and his apparent commitment to it, so the OP was suggesting that the success of the space

Obama has no similar dreams of space exploration to my knowledge, no equivalent public commitment, so putting a bullet to his head doesn't create another martyr for NASA.

Exactly. Plus, putting a bullet in Obama's head will do nothing but give us another crappy President: Biden. A bullet in his head would make things even worse, by putting Pelosi in charge. I'm not sure who takes over if Pelosi is killed, but looking at our Congresscritters, it probably wouldn't be an improvement.

Let them take down my IP. I didn't wish for anything. I was pointing to, as other have remarked, the concept that Kennedy's death got NASA a ton of public support since one of his dreams was to get a man on the moon by the end of 69. This also can be seen in MLK's legacy. The assassination of MLK made a lot of fence sitters sympathetic to his cause.

Hell, we even had people push the health care bill on the public sympathies of Ted Kennedy's death. Political causes will find their own martyrs where they can.

Most "green" targets are being set like this. The UK has a target to halve CO2 emissions by 2050. But there's no interim 5 year targets. It will be just like Kyoto - everyone will get a year or 2 away from the date and it will be "oops, we didn't meet it". The people in charge can blame the last lot for not getting it started early enough and it's soon forgotten.

Obama couldn't give a rat's fuck about landing people on an asteroid. He just wants to get a few geeks to vote for him now because it sou

Of course it's possible that Kennedy also didn't really give a rat's fuck [hey, can they do that?] about it either, and that his public position was motivated by nothing more than the Cold War. Nevertheless, regardless what he did or didn't think personally, publicly he did in fact make a determined effort to set that as a goal for the nation. Obama, as you said, has certainly done nothing similar. Did Kennedy foresee the need for diversifying and decentralizing Homo sapiens and finding new resources for

And what timescale did Kennedy give for man to go to the moon? It was about 8.5 years, wasn't it? Or the sort of timescale where he could actually be judged on progress. He delivered his commitment on TV including directly asking Congress for the money. What's Obama done? "Promised" that NASA will get $6bn over 5 years (about half of the money Kennedy asked for in 1961). And Kennedy didn't give a damn about diversifying and decentralising Homo sapiens. It was about winning a propaganda victory in the cold w

Even back then, most folks had the attention span of a fruit fly - I'd bet on JFK getting killed as the main impetus, all dressed up as 'legacy'. It's the only explanation that actually makes sense.

After all, it's not as if the fact that NASA continued pushing for a pre-1970 "in this decade..." landing (in spite of Johnson and Nixon's penchant for farting around with Vietnam) just for the hell of it...

There are a number of Near Earth Asteroids that are dynamically easy to reach (i.e., with very low delta-V's). The "Plymouth Rock [usra.edu]" presentation to the NASA Small Bodies Assessment Group (SBAG) last year lists 12 that could be reached with Orion. These are being found fairly rapidly, so there is no shortage of targets.

I love how you just throw this out there, as if Orion actually existed on anything but paper. It's like people around here talking about fast breeder reactors as if they'd been magically scaled up to production when no one was looking...

As far as I can tell, there is nothing magic or technically complex about Orion that would make it impossible to build. Further, I think by saying "Orion" they really mean Orion-like vehicles. I can think of at least two off the top of my head right now: the new Boeing proposal and Dragon from SpaceX.

There are no aerodynamics to worry about, only torsional stresses caused by the low thrust engine.

We keep thinking in terms of rockets - and clean lines - just to make it into orbit - but once in orbit that no longer matters if you don't plan to land it again.

You wouldn't be moving the pig with chemical engines, you'd be using plasma or solar sails where the forces can be measured in grams. If you want decent gravity, add a couple of outriggers and spin the whole thing - that would be a lot more force than

I always wondered why the last stage(s) of the old rockets, and the big tanks on the shuttle, were dumped rather than carried into orbit for use as habitats, storage, spares, etc. They contained fuel tanks and rocket engines (for the old stages) and presumably a 'little' more fuel could have carried them all into orbit where they could have been attached to each other to make a huge 'station'. Boost them to the Moon, or Mars, for use a raw materials for when we get there maybe, or clean them and add them t

Because very shortly after they've been cast aside, expended stages quickly become tumbling masses unsafe to approach. With ongoing collisions of space debris, they also would become new sources of space junk themselves.

Because there was not an immediate need for them, and (to be blunt) because in many ways "the system" is set up to spend money building things, not to save money reusing things. Look at the Jules Verne [wikipedia.org] - a man-rated cargo carrier (i.e., an actual pressurized spacecraft) that was used once, filled up with garbage, and disposed of via re-entry.

There were many plans in the early days of the space shuttle to take the Space Shuttle External Tank (which certainly could be used in orbit - it actually is brought to orbit, and then energy is expended to make sure it re-enters immediately) and make them into space stations in the Skylab fashion. (Skylab was the 3rd stage of a Saturn V outfitted as a space station - this was originally intended to be launched "wet" in a 1973 Venus Flyby Mission [wikipedia.org]. Nixon killed this mission and all plans and infrastructure for manned deep space flight and we are still trying to get them back.)

The Space Shuttle External Tank space station could have been done, there was even a start-up I had a remote involvement with trying to make one into a space hotel, but such ideas got no support and no funding and all died on the vine.

Look at the Jules Verne [wikipedia.org] - a man-rated cargo carrier (i.e., an actual pressurized spacecraft) that was used once, filled up with garbage, and disposed of via re-entry.

Progress could also hold atmosphere although a bit smaller. There is no airlock to the garbage scow so it has to be capable of holding pressure. The problem remains with Progress or Jules Verne that you would then need somewhere to put your rubbish and something to shoot it with to make it burn up in the upper atmosphere. I h

The problem remains with Progress or Jules Verne that you would then need somewhere to put your rubbish and something to shoot it with to make it burn up in the upper atmosphere.

Why ? Material is brought at great expense to Earth orbit, why not keep it there for potential future re-use ?

The ATV is a 20 ton spacecraft, with steering & fully man-rated. ISS Node-3 is 19 tons. Why not save up 3 or 4 years of (once per year) ATV supply vehicles, and make the asteroid mission out of those ? That would be 60 o

Its all the more depressing when you realize that only the Chinese actually have the disposable income to do space with astronauts these days. Isn't it about time NASA fired all these dreamers and got on with the robotic future?

""Brian Wilcox, a JPL roboticist, spoke at a NASA workshop about the possibility of detaching one of the International Space Station's modules and using it as the primary living space for astronauts on a trip to an asteroid."

And, with sufficient wing area, pigs could fly.

Seriously, Tranquility (Node 3) would require such major reconstruction to do this that they might as well build a new module. Not only is it not built for the thermal, radiation, and micrometeorite enviroment beyond LEO... It's also not

... we need a few billion more to 1) actually make it go somewhere, 2) shield astronauts from radiation during the trip, and 3) make it have enough food, water, air, power, etc. for the crew to survive.